This invention relates to a multilayer packaging laminate for packaging applications, especially in packaging food products such as barrier bags.
Multilayer plastic laminates are commonly used as packaging materials for food products. These laminates are generally extruded or coextruded and typically include at least four layers of plastic materials. Typically, the inside layer or layer exposed to the food is a seal layer which contacts the food and which may be heat sealed in order to form the packaged product.
These multilayer laminates generally contain a core layer bonded to the seal layer; a barrier layer bonded to the core layer, such as saran or ethylene vinyl alcohol copolymer (EVOH) as an oxygen barrier; and an outside or abuse layer bonded thereto. The outside layer is the considered the abuse layer, that is, the out side layer is the exposed layer and should be abrasion resistant while having good optics and having grease resistance.
A problem with these laminates is applied seal delamination. That is, when the inside or seal layer is bonded together to form a heat seal, often the outside or abuse layer will delaminate from the barrier layer which is bonded thereto. It is highly desirable to provide an outside or abuse layer which enjoys the desirable characteristics needed in such a layer while at the same time is not subject to applied seal delamination.
Conventionally, adhesive materials are applied between the barrier layer and the outside layer; however, these do not entirely avoid the problem of applied seal delamination.
Accordingly, it is a principal object of the present invention to provide a multilayer packaging laminate suitable for use in packaging applications which has excellent packaging characteristics.
It is a further object of the present invention to provide a laminate as aforesaid wherein the outside layer is bonded to a barrier layer, is abrasion resistant and does not delaminate from the underlying barrier layer on heat sealing.
Further objects and advantages of the present invention will appear hereinbelow.